/*
 * Copyright (C) 2016 Jared Boone, ShareBrained Technology, Inc.
 *
 * This file is part of PortaPack.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifndef __JTAG_TAP_H__
#define __JTAG_TAP_H__

#include "jtag_target.hpp"

#include <cstdint>
#include <cstddef>
#include <vector>

namespace jtag {
namespace tap {

class bits_t {
   public:
    constexpr bits_t()
        : p{nullptr},
          count{0} {
    }

    constexpr bits_t(
        const size_t count,
        const bool default_value = true)
        : p{nullptr},
          count{count},
          default_value{default_value} {
    }

    constexpr bits_t(
        const uint8_t* const p,
        const size_t count)
        : p{p},
          count{count} {
    }

    size_t length() const;

    explicit operator bool() const;

    bool operator[](const size_t index) const;

   private:
    const uint8_t* p{nullptr};
    size_t count{0};
    bool default_value{false};

    size_t bytes() const;
};

enum class state_t : uint8_t {
    /* Ordinal values are important for "routes" values, and to match XSVF definitions. */
    test_logic_reset = 0,
    run_test_idle = 1,
    select_dr_scan = 2,
    capture_dr = 3,
    shift_dr = 4,
    exit1_dr = 5,
    pause_dr = 6,
    exit2_dr = 7,
    update_dr = 8,
    select_ir_scan = 9,
    capture_ir = 10,
    shift_ir = 11,
    exit1_ir = 12,
    pause_ir = 13,
    exit2_ir = 14,
    update_ir = 15,
};

class TAPState {
   public:
    constexpr TAPState()
        : _state{state_t::test_logic_reset} {
    }

    state_t state() const;
    void advance(const bool tms);
    bool advance_toward(const state_t desired_state) const;

   private:
    state_t _state;
};

class TAPMachine {
   public:
    constexpr TAPMachine(
        jtag::Target& target)
        : target{target} {
    }

    void set_run_test(const uint32_t value);
    void set_repeat(const uint8_t value);
    void set_end_ir(const state_t state);
    void set_end_dr(const state_t state);

    bool shift(const bits_t& tdi, const bool end_tms) {
        return shift(tdi, {}, {}, end_tms, nullptr);
    }

    bool shift(const bits_t& tdi, const bits_t& tdo_expected, const bits_t& tdo_mask, const bool end_tms, std::vector<bool>* from_device);

    bool shift_ir(const bits_t& tdi_value, const bits_t& tdo_expected = {}, const bits_t& tdo_mask = {});
    bool shift_dr(const bits_t& tdi_value, const bits_t& tdo_expected = {}, const bits_t& tdo_mask = {});
    std::vector<bool> shift_dr_read(const bits_t& tdi_value);

    void state(const state_t state);

    void wait(const state_t wait_state, const state_t end_state, const uint32_t wait_time);

   private:
    jtag::Target& target;
    TAPState tap{};

    uint32_t _run_test{0};
    uint8_t _repeat{0};
    state_t _end_ir{};
    state_t _end_dr{};

    bool clock(const bool tms, const bool tdi = false);
    void advance_to_state(const state_t desired_state);
    void delay_us(const uint32_t microseconds);

    void shift_start(const state_t state);
    void shift_end(const state_t end_state, const uint32_t end_delay);

    bool shift_data(const bits_t& tdi, const bits_t& tdo_expected, const bits_t& tdo_mask, const state_t state, const state_t end_state, const uint32_t end_delay);
    std::vector<bool> shift_data_read(const bits_t& tdi, const state_t state, const state_t end_state, const uint32_t end_delay);
};

} /* namespace tap */
} /* namespace jtag */

#endif /*__JTAG_TAP_H__*/
